New York City is filled with multifamily apartment buildings built before World War II; we often refer to them as prewar buildings. Of course, many wars have been waged since 1945, so I won’t use “prewar” as a description. A common trait of these buildings, however, is that they are heated with steam boilers. Builders didn’t stop building multifamily housing with steam heat after the war—steam heat has been as common as hot-water heat in these large buildings for some time. The multifamily building at 179 Henry Street was built in 1965 with HUD financing for senior living. The heating system was designed to provide two-pipe steam heat to the building from two large firebox boilers burning #6 fuel oil. This is how it was in 1965 and through the summer of 2010. (For a snapshot of the building before the retrofit in 2010, see “Preweatherization Stats.”)